![]() Portable coordinate measuring instruments such as articulated arm coordinate measuring machines (AACMMs) need to be periodically evaluated according to international standards and guidelines. ![]() Finally, a comparison between the optimized parameters and the nominal parameters is discussed, showing the advantages of using the indexed metrology platform (IMP) in the optimization procedure. Moreover, the kinematic modeling of the AACMM is developed, and the optimization of the arm kinematic parameters to minimize the measurement error is carried out in terms of eight objective functions. In this work, a kinematic parameter identification procedure of an AACMM by means of an indexed metrology platform is presented. Nevertheless, an important drawback of these type of instruments are the time-consuming, tedious, and expensive tasks inherent to their verification and kinematic parameter identification procedures. Within this context, a measuring system group that has gained great importance in the field of high precision dimensional verification are the portable coordinate measuring machines (PCMMs) such as articulated arm coordinate measuring machine (AACMM). ![]() Ī still current challenge of paramount importance for manufacturing metrology is the industry and laboratories’ increasing demand for faster inspection and verification measuring procedures to determine the conformance of products to dimensional or functional requirements. These errors were used to evaluate the measuring volume of the AACMM by calculating the root mean square value. ![]() Since in three of the orientations of the ball bar gauge five spheres were measured and in the remaining ones four spheres were measured, we were able to materialize 252 distances between centers (for all six platform positions) and compared them to the nominal distances to obtain 252 distance errors. The orientations of the ball gauge bar and the spheres measured in each orientation are presented in Figure 25. Nevertheless, it must be noted that by evaluating these five orientations in the six positions of the platform will be the equivalent to locating the ball bar gauge in 30 different orientations with respect to the AACMM, more than the ones suggested by the norm which allows to evaluate a greater measuring volume in a significant less time and physical effort. In this work we selected five orientations from the 20 recommended by the norm. The ASME B89.4.22 volumetric test recommends locating the ball bar gauge in 20 different orientations around the AACMM in order to evaluate most of its measuring volume. The calibrated gauge object used consists of a ball bar gauge with the distances between the spheres centers calibrated. The AACMM used in the volumetric verification is a Faro Platinum ( Figure 24) with a diameter measuring volume of 2.4 meters and a 2-2-3 measuring configuration type and a volumetric precision reported by the manufacturer of ± 0.043 mm. To verify the correct functioning of the platform, a volumetric verification of an AACMM was carried out based on the ASME B89.4.22 norm. (17) – (19) and (20) – (22) meet the conditions of orthogonality and normality of the HTM found respectively.
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